Electrical condenser.



W. W. DEAN.v

ELECTRICAL CONDENSER.

APPLICATION FILED 00125, 1909.

Patented Oct. 4, 1910.

UNITED STATES PATENT onion.

IVILLIAM W. DEAN, OF ELYRIA; OHIO, ASSIGNOR TO THE DEAN ELECTRIC COMPANY, OF ELYRIA, OHIO, A CORPORATION OF OHIO.

Specification of Letters Patent.

Patented Oct. a, rain.-

Original application filed January 28, 1909, Serial No. 474,772. Divided and this application filed October 25, 1909. Serial No. 524,310.

To all whom it may concern.

Be it known that I, WILLIAM W. DEAN, a citizen of the United States, residing at Elyria, in the county of Lorain and State of Ohio, have invented certain new and useful Improvements in Electrical Condensers; and I do hereby declare the same to be a full, clear, and exact description of the invention, such as will enable bthers skilled in the art to which it appertains to make and use the same.

This application is a division of my application Serial No. 474,772, filed January 28, 1909.

My invention relates to an electrical condenser commonly used in connection with electrical apparatus; such as, telephone. exchanges, etc., in which it is desirable to store charges of electricity, as desired. Heretofore in the art, it has been customary to construct condensers of this class by assembling two metallic sheets or plates with interposed sheets or thicknesses of di-electric between them. It has been found convenient in the past to accomplish this by using stri s of tin foil to form the conducting surfaces and using strips of thin paper between the strips of tin foil to prevent their coming in contact and winding several strips together inthe form of a roll as a result of which aconsiderable amount of surface is available for retaining the electrical charge. In constructing condensers in the manner described it has frequently happened in the past that particles of dirt or conducting matter would be wound in between the severallayers of paper and tin foil in such a manner that the subsequent manipulation of the condenser in reparing it for use, would cause the partlcles to puncture the di-electric between adjacent cont-acting surfaces and thus short circuit the condenser. It has been customary in the past to clear condensers of short circuit thus established, by burning out the conducting path thus formed between the strips and tin foil by means of a bank of condensers which have been'charged'from a source of direct current and by applying direct current to the terminals of the condenser to be cleared. In many cases this process fails to"'clear the condensers of short circuits, ow-

ing to the fact that the conducting path between the layers and tin foil permits sufiicie'nt current to flow to, melt a considerable quantity of the tin foil before the conducting path is burned out, as a result of which the tin runs together through the opening formed in the di-electric and a permanent short circuit is a result which cannot be burned out and the condenser must be thrown away.

It is an object of thisinvention to improve the construction of electrical condensers in such a manner that a sufiicient amount of metal is not available during the burning out process to permanently short circuit the metallic contacting surfaces of the condenser. This I accomplish by using but one strip of tin foil and in connection with such strip to constitute a second conducting strip of the condenser, a strip of thin paper to one side of which conducting material in finely divided condition is so applied that it forms a continuous conducting surface. I may use several strips of this paper in connection with the strip of tin foil, or I may use a-strip of paper for both sides covered with the finely divided conducting material and may placetwo of the conducting surfaces in contact with each other. The strip of tin foil and the coated strip or strips of paper may be wound together in the form of a roll in accordance with any of the well known ways for accomplishing this result,

strips of thin paper being used to prevent either of such conducting surfaces coming in contact with the other conducting surfaces. After the rolls are formed, the condensermay be finished in any of the well known ways common in the art, which are not indicated in detail here, since they form no part of this invention.

As a result of the improved construction described, the amount of metal which is subject to the heating action of burning out a short circuit is greatly reduced, and short circuits that would otherwise permanently short*circuit the condenser and destroy the same by the burning out process, as described above, may be readily removed, since the amount of metal melted in the process is very small comparatively and comes almost erable number and it is frequently necessary to burn out short circuits in these condensers after they are placed in use, since the imperfection would not be of a serious enough nature to give any indications of their presence at the time of testing the condensers at the factory. The possibility of clearing these condensers of short circuits that may develop in this manner, is a great advantage. Furthermore, condensers constructed in accordance with my invention are so much less liable to be short circuited by the accidental puncturing of the di-electric by the accidental application of high voltage ringing current or the accidental crossing of conductors connected to the condensers with high voltage power circuits.

. Tn constructing my improved condenser, the strip or strips coated with finely divided conducting material may be prepared and used in a number of ways. The strip may be coated on both sides, if desired, one side may be placed directly in contact with a strip of tinfoil and thus serve to establish a more intimate relationship between the two conducting surfaces of the condenser. I may use two strips of coated paper placing the conducting surfaces face to face and thus producing in effect a single conducting surface. It is to be understood that with any of the constructions described, additional strips of paper may be used between the conductin sired di-electnc strength.

The several drawings which illustrate my invention are as follows: s

Figure 1 shows an arrangement consisting of two strips of coated paper placedface to face, a strip of tin foil and a strip of plain paper all wound together in the form of a roll in such a manner that the conducting surfaces are kept separate from each other. Fig. 2 shows an arrangement in which a strip of paper coated on each side, a strip of tin foil, and a strip of plain paperare wound together in the form of a roll so that bodiment of n the strip of tin foil is in contact with one of the surfaces of the coated strip and the other conducting surface is prevented from coming in contact with the strip of tin foil.

Referring to the drawings and to the eminvention there shown, in Fig. 1 I have s own a condenser consisting of two strips of insulating material each partly covered on one side by finely divided conducting material. The surfaces upon which the' conducting material is placed, are situated so that the conducting material is in contact. 1 is the strip of paper bearing a strip of conducting material 2. 1 is a strip of insulating material bearing, the strip of conducting material 2. 3 is a strip of tin or other metallic foil. 4 is a strip of insulating material, preferably pa er. As shown, the strip of tin foil is place so that surfaces to furnish any decareer one of the strips of paper intervenes be tween it and the two surfaces of finely di= vided material. Strip 4 is placed on the outside, and the whole is rolled up into a roll as shown at 5.

In Fig. 2 I show at 1 a strip of paper on both sides of which a strip of finely divided conducting material has been de osited, as shown at 2 3 is a strip of tin oil and a, a strip of paper. These are placed so that one of the strips of finely divided conduct ing material engages the strip of foil, and the strip of paper a is on the other side of the strip of foil. The whole is then rolled together into a roll 5.

It is to be understood that the rolls formed in accordance with either of the arrangements described above, may be sub sequently treated in any of the well known ways; as, for example, boiling in parafiin, pressing, placing in suitable cases and the like, by which the finished-condenser is produced. These subsequent steps in the con-- struction of the condenser, however, form no part of the present invention which consists essentially in the construction and arrangement of the strips forming the condenser. v

While I have shown my invention in the particular embodiment herein described, I 95 do not Wish to be limited thereby, and contemplate'numerous and extensive departures in the form and details of the a paratus here shown which do not depart trom the spirit of the invention.

ll claim:

1. In an electrical condenser, the combination of strips of insulating material, one adapted to act as an insulatorat low voltages, but adapted to be punctured at high voltages, thin layers of conducting material each deposited upon a surface of one of said strips, said thin layer of conducting material adapted to be dissipated at the punctures to isolate said punctures from the remainder of the layer and a strip of metallic foil of relatively low resistance, all wound together in a roll, such strips of insulating material and metallic foil being so disposed relative to one another that two of said conducting layers are in contact and both are separate froin a third by a strip of insulating materia A 2. In an electrical condenser, the combination of strips of paper, one adapted to act as an insulator at low volta es but adapted to be punctured at high vo tages, thin layers of conducting material, each placed 'upon a surface of one of said stri s, said thin layers of conducting material a apted to be dissipated at the punctures to isolate said punctures from the remainder of the layer, and a strip of metallic foil of relatively low resistance, all wound together in a roll, such strips of insulating material and metallic foil being, so disposed relative to one another that two of said conducting layers are in contact and both are separated from a third by a strip of insulating material.

3. In an electrical condenser, the combination of strips of insulating material, one adapted to act as an insulator at low voltages, but adapted to be punctured at high voltages, thin layers of conducting material, each placed upon a surface of one of said strips, said thin layers of conducting material adapted to be dissipated atgthe punctures to isolate said punctures from the remainder of the layer, and a strip ofmetallicfoil, the

layers and strips being so arran ed relative 5 ture in presence of two Witnesses this 22 day 20 of Oct.,1909. 7

WILLIAM W. DEAN.

Witnesses:

C. A. SEVEROOOL F. O. Rrcrray. 

